1. Field of the Invention
The present invention relates to an electrical tool including a permanent magnet motor as a driving source.
2. Description of Related Art
A permanent magnet motor such as a commutator motor capable of obtaining a high output with a small size is used as a driving source of an electrical tool (for example, see Patent Document 1). In an electrical tool using a commutator motor as a driving source, as shown in FIG. 7, a commutator motor 106 includes a stator 116 fixed to an inner circumferential surface of a motor case 105 and a rotor 117 rotatably disposed in the stator 116. In addition, plates 122 and 123 including a plurality of slot portions having the substantially same shape as that of slots of a rotor core 119 and protrusions are disposed at the both axial ends of the rotor core 119 of the rotor 117.
As shown in FIG. 7, in the electrical tool including the motor case 105 which is integrally formed in a tube shape, the commutator motor 106 is mounted by previously inserting and fitting the stator 116 including a permanent magnet 118 into the motor case 105 and then inserting a rotor unit including the rotor 117 thereinto.
The rotor unit is formed by mounting a commutator 120, a cooling fan 111, and bearings 108 and 109 on a shaft 107 for supporting the rotor core 119. Upon inserting, the bearing 109 passes through the stator 116 in the motor case 105 and fitted into a bearing portion 105a of the motor case 105.
Patent Document 1 is Japanese Patent Unexamined Publication No. 2004-080969.